1. Field of the Invention
The present invention relates to a driving apparatus and a control method for an electric actuator.
2. Description of the Related Art
Japanese Unexamined Patent Publication No. 2001-254637 discloses an apparatus for diagnosing the malfunction of a variable valve lift mechanism which varies a lift amount of an engine valve by an electric actuator.
In the above diagnosis apparatus, it is judged that the variable valve lift mechanism is malfunctioned, when a change in lift amount is smaller than a predetermined value and also when an absolute value of the deviation between the lift amount and a target value exceeds a predetermined value.
In the case where a computing unit that computes an operation amount of the variable valve lift mechanism is operated normally, it is possible to execute the failure diagnosis of the variable valve lift mechanism and the processing based on a result of the failure diagnosis.
However, if the computing unit fails, it becomes impossible to appropriately execute the failure diagnosis and the processing based on the result of the failure diagnosis. As a result, there is a possibility that the lift amount of the engine valve is abnormally controlled.